Sarcopenia and cachexia in chronic diseases: from mechanisms to treatment

Two main manifestations of wasting disorders in chronic disease are cachexia and sarcopenia. Due to shared pathological features, including impairments in systemic inflammatory responses, neurohormonal activity, and metabolic systems, the 2 disorders can present with similar symptoms (tissue depletion, dyspnea, anorexia, asthenia, fatigue, and impaired physical performance). Wasting disorders are associated with reduced quality of life and increased mortality. Cachexia is characterized by systemic tissue depletion with weight loss, and sarcopenia, by skeletal muscle loss accompanied by diminished muscular strength and physical performance. Wasting syndromes can be identified based on clinical criteria as well as with the use of multiple imaging and diagnostic techniques. Additionally, blood biomarkers can be used for diagnosing wasting disorders. In the past decade, intensive research has focused on new therapeutic strategies within a multimodal approach, which embraces nutritional support, physical activity, and targeted pharmacological therapy. Despite some initial promising therapeutic results for selected novel agents, guideline-recommended pharmacotherapy is not yet available for cachexia or sarcopenia. More research is needed to better understand these wasting disorders and learn how to treat them.